For ease of comprehension, the subject invention will be disclosed in terms of a cardiac-signal apparatus; but this is not to be construed as a limitation, as other uses will be discussed during the disclosure.
It is well known that near miracles are being performed in the treatment of heart difficulties; but it is not as well known that many serious cardiac distresses are encountered in post-treatment situations. These cardiac distresses may range from actual cardiac seizures, through relatively unimportant cardiac misfunctions, to groundless fears brought on by other unrelated conditions.
Such cardiac distresses may arise at any time or place--at home, while walking, while boating, in restaurants, at meetings, etc. Of course, a doctor should be contacted immediately; but, too often, the patient tends to wait out the cardiac distress. Some of the reasons for the waiting-out period are the desire not to bother the doctor, the possible embarrassment of reporting false symptoms, the fear of facing the actual cardiac review, etc. However, when a patient does contact the doctor, there is generally a need for a cardiac waveform--known as an EKG or an ECG; and this requires a rush trip to a hospital, medical office, or the like. Thus, a patient's fear of a cardiac-distress situation is worsened by an incipient panic situation and its attendant expense.
There are approximately 500,000 coronary deaths each year in the United States; and fifty to seventy percent of these are classed as "sudden" deaths. "Sudden death" is defined as death occurring within twenty-four hours of the onset of acute symptoms which begin outside of a hospital.
The cause of death in most of cases is due to ventricular arrythmia, which if detected earlier might have been avoided.
One of the basic instruments used by a doctor in the identification and treatment of heart disease is the electrocardiograph (EKG).
The EKG detects the electrical potentials generated by the action of the heart muscle. The permanent record of them is called an electrocardiogram.
Cardiographic analysis of a person with heart disease is frequently made at all stages of the disease.
When a patient is convalescing from one or a series of heart attacks or past heart surgery, the doctor may wish to obtain a daily or weekly electrocardiogram in order to check on his progress.
This usually requires that the patient go to the doctor's office or to a hospital for tests. This may be difficult, as well as expensive for a patient, particularly if he is in a physically and emotionally weakened condition.
It frequently happens that a person is stricken by a heart attack at work, at home, at a restaurant, on a boat, in an airplane or other inconvenient location. In most of these cases, an electrocardiogram could not be readily made.
Most people, even those with a history of heart disease, hesitate to call their phyician at the onset of symptoms. The reasons for this are many and varied. Sometimes, they do not want to bother him, particularly if it is late at night, or on a weekend--and think it is probably nothing anyway. Many, particularly elderly patients, do not call the hospital or physician because it takes much effort to go to the doctor or to a hospital.
There are numerous prior-art apparatuses that attempt to solve the above problem by sending the patient's EKG over the telephone system. Invariably, the proposed solutions require chest electrodes that utilize a cardiac gel; they generally require "hard-wiring" between the electrodes and the apparatus; and they require a conversion apparatus that converts the cardiac signal (from the electrodes) to a cardiac sound. The conversion apparatus usually comprises a cradle for a telephone handset; and the proper cradling of the handset applies the cardiac sound to the handset mouthpiece for telephonic transmission. Attention is directed to U.S. Pat. Nos. 3,426,150; 3,769,956; 3,872,251 and 3,872,252.
While these prior-art apparatuses improve the patient's mobility, they require that he carry around numerous and relatively burdensome components.
Other proposed apparatuses suggest the use of a radio transmission--which requires even more complex apparatuses.
These apparatuses have a number of objectionable features. The first objectionable feature is that they require the use of a cardiac gel smeared onto the patient's chest where the electrodes are to be placed. Cardiac gels are used to reduce the "interface" electrical resistance between the patient's skin and the electrode proper, in order to encourage the flow of the minute electric current that forms the electric cardiac signal. Unfortunately, cardiac gels tend to be irritating to the skin; and a person who requires frequent applications of the cardiac gel soon develops a painful skin condition.
A second objectionable feature of the prior-art apparatuses is the use of electrodes that are intentionally small--so that they may pick up cardiac signals from precisely designated body areas--this often being desirable for precise diagnosis, because the EKG varies somewhat with the location of the electrodes. Thus, incorrect placement of the small electrodes used by the prior art apparatuses may produce an undesired EKG.
A third objectionable feature of the prior-art apparatuses is the presence of hard-wiring extending from the electrodes on the patient's chest to the conversion apparatus. Even though these wires are made as flexible as possible, they must be strong enough for repeated use. As a result, patient movement or lack of care by the attendant may pull off the small poorly-adhered electrodes.
Another objectionable feature of the prior-art apparatuses is that the patient has to carry several pieces of equipment plus electrodes and gel.
Still another objectionable feature is that the patient has to assemble the apparatus, plug in leads, put gel on leads, attach leads to the chest, set several controls on the equipment; and cradle the telephone on the equipment.
Still another objectionable feature is the need to set various switches and pushbuttons, etc.
Still another objectionable feature is the need for an experienced attendant, if the patient's condition is such that he cannot direct the activities.
A still other objectionable feature is that the patient must purchase a relatively expensive apparatus, and must carry this bulky apparatus with him wherever he goes.
Thus, despite numerous proposed prior-art apparatuses, there is still a need for an improved cardiac-signal apparatus.